Conventionally, Patent Document 1 (International Patent Publication No. WO 0007836 A1) discloses regarding a vehicle air conditioner, which is provided with an evaporator of a refrigerant cycle as a cooling heat exchanger. The cooling heat exchanger is used for cooling air to be blown into a vehicle compartment. The vehicle air conditioner is made to prevent bad odor generation from the evaporator.
Specifically, the air conditioner in Patent Document 1 controls a refrigerant discharge capacity of a compressor of the refrigerant cycle, such that an evaporation temperature of refrigerant flowing in the evaporator is made to be higher or lower by a predetermined degree than a dew-point temperature of the blown air flowing into the evaporator. In this case, an outer surface of the evaporator is not repeated to be dry and wet frequently, so that the bad odor generation in the blown air is limited.
However, in Patent Document 1, for example, even if the outer surface of the evaporator is in a dry state in which the bad odor generation in the blown air is restricted, the compressor is operated such that the evaporation temperature of refrigerant flowing in the evaporator is made to be lower by the predetermined degree than the dew-point temperature of air flowing into the evaporator. That is, even in a situation where bad odor is difficult to occur in the blown air, the compressor is operated. Such unnecessary operation of the compressor may be a factor in increasing energy consumption of the vehicle air conditioner.